Asphalt compositions such as asphalt emulsions can be used in the production of paved surfaces. One issue in the use of these asphalt compositions is that they can produce “tracking.” For example, a tack or bonding coat also can be applied to a base or substrate layer in advance of the application of the next pavement layer. In the meantime, construction or other vehicles are expected to travel over the tack coat without significantly damaging or reducing the effectiveness of the coating. Such damage often occurs, however, when the tack or bonding coating is picked up on the tires or tracks of vehicles traveling over the coated surface. Where this occurs, the asphalt compositions often are tracked onto other pavement surfaces causing disruption to the surrounding area. This tracking also reduces the effectiveness of the tack coat by displacing a portion of the intended volume from the area awaiting a new pavement layer.
Insufficient adhesion between a new layer of pavement and an existing base course, a previously laid pavement layer, or a prepared pavement surface can cause pavement separation and cracking during construction of the structure, as well as subsequent failures and premature deterioration of the pavement structure and/or surface. Such conditions often require costly repairs, can cause damage to vehicles traveling on the surface and may cause dangerous traffic conditions threatening damage to property and injury to vehicle passengers.
In addition, certain asphalt products can require a relatively long cure time (as long as 2 to 7 days or more) before traffic is permitted to pass over the treated area. When the next pavement layer cannot be laid down immediately, the cured tack coat remains exposed for extended periods and remains tacky and sticky. Accordingly, vehicle traffic over the treated surfaces often must be shut down until another layer of pavement is applied, and if traffic is allowed to pass, the asphalt tack coatings frequently adheres to the tires and tracks of vehicles traveling over the coated surfaces. This frequently results in lifting and damage to the tack coat and undesirable tracking of the coating to other surfaces via the vehicle tires and tracks.
Damage to the tack coating can substantially interfere with the ability of the coating to properly bond and/or fuse the pavement layers or base together. As a result, the pavement layers may slip or separate with the passage of traffic over the structure and time. This type of damage also may permit water penetration into the pavement surface, which can result in further deterioration due to freeze-thaw cycles or similar stresses. As a result, multiple applications of the tack coat may be required to obtain the desired adhesion between the pavement layers at a significant loss of efficiency and increase in cost. Furthermore, where the coatings are tracked to other surfaces by vehicles, extensive cleanup may be required adding to the expense of a project.